<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>caseTamplate</title>
</head>
<style>
  *{
    margin: 0;
    padding: 0;
  }
  .clearfix::before,
  .clearfix::after{
    content: '';
    display: table;
  }
  .clearfix::after{
   clear: both;
  }

</style>
<body>
<div class="clearfix"></div>
</body>
</html>
